Body fluid drains and containers are well known in the art. For example, there are collection devices for urine and others that drain and collect spinal fluid. None of these devices are able to easily control the drainage rate of the fluid as a function of time.
In connection with the drainage of cerebrospinal fluid (“CSF”), for most people, the body produces 450 ccs of CSF over a 24 hour period which fills the subarachnoid space in the body. There are many instances where it may be advisable and/or necessary for some of the CSF to be drained. For example, during certain medical procedures such as brain surgery, the surgeon may wish to drain some of the CSF in order to retract the brain. In addition, in some brain and spinal surgeries where the dura mater is penetrated, the CSF would need to be partially drained to keep pressure off the wound site in order to allow it to heal. Also, in certain head trauma cases where CSF is collecting in the cranial cavity, it may be preferable to drain some of the CSF from the subarachnoid space in the lumbar spinal region to relieve the pressure on the brain.
Conventional methods of draining CSF involve tapping into the cranial or subarachnoid space in the spinal column and draining the excess CSF through a catheter tube into a collection bag. The amount of drainage must be regulated, as if there is too much drainage, a patient can be irreversibly injured or can be fatally injured.
Unfortunately, the rate at which the CSF drains is not linear fashion. For example, the CSF can drain at 1 cc per hour and then suddenly drain 5 ccs in 10 minutes. Since there are irreversible and potentially fatal consequences if too much CSF is drained, the volume of the drainage has to be constantly monitored by a nurse. Due to the demand on a nurse's time and the non-linearity of the drainage, there is a potentially fatal margin of error. Thus, an apparatus that continuously monitors and controls the drainage of the CSF would be of great benefit to the art.